DESCRIPTION:
L=27" (69cm), WS=69" (175cm). Sexes similar. Overall black,
with pink head. In flight, wings show dark leading edge and lighter trailing
edge and wings are held up in a V pattern (different from most hawks and
eagles).
NATURAL HISTORY: Feeds on dead animals (carrion) found by both sight and
scent (unusual among birds). Vultures save energy by soaring, using upcurrents
of air (thermals) to stay aloft. They also save energy by lowering their
body temperature (torpor) at night
and then basking while perched (with wings outstretched ) to warm back
up in the morning. Their black plumage helps them absorb heat while basking
then helps keep them keep cooler (compared to white plumage) while soaring
during the hot day looking for carrion (see below).
To cool themselves down when too hot, they urinate on their unfeathered,
blood vessel-filled legs, allowing for evaporative cooling but staining
their legs white.

HOW
CAN BLACK BE AN ADAPTATION TO THE DESERT?

Having
black feathers/fur/exoskeleton helps black animals heat up in the morning
and cool off during the day. Here's how it works.

Compared
to white, black absorbs more heat, but stops more of the sunlight from
penetrating deeper toward the body. When the air is still, during the
cold morning hours, the heat absorbed into the black surface has time
to conduct inward to the body, heating the animal. During the hotter part
of the day, when the animal is flying or running and/or the wind is blowing,
the wind (by convection) quickly whisks away the heat that is absorbed
by the outer surface before the heat has time to conduct inward to the
body. Thus the animal remains cooler than if the sunlight was able to
penetrate through white surface into the body.